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GCN Circular 21331

Subject

GRB 170711A: Swift-BAT refined analysis

Date

2017-07-12T19:23:15Z (7 years ago)

From

Hans Krimm at NSF/NASA-GSFC <hkrimm@nsf.gov>

C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC), J. R. Cummings (CPI),
V. D'Elia (ASDC), H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC),
D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU),
T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):

Using the data set from T-240 to T+962 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 170711A (trigger #761622)
(D'Elia, et al., GCN Circ. 21321Loading...
 
 ).  The BAT ground-calculated position is
RA, Dec = 45.782, 47.845 deg which is
  RA(J2000)  =  03h 03m 07.7s
  Dec(J2000) = +47d 50' 41.2"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.

The mask-weighted light curve shows a single FRED-shaped peak, starting at
T-2 sec, peaking at T+0 sec and decaying to background by T+6 sec.  This is
preceded by some weak, soft emission beginning at about T-25 sec.
T90 (15-350 keV) is 31.3 +- 7.6 sec (estimated error including systematics).

The time-averaged spectrum from T-31.66 to T+15.37 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.75 +- 0.10.  The fluence in the 15-150 keV band is 1.4 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+0.02 sec in the 15-150 keV band
is 4.8 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/761622/BA/